/*
 *
 * Copyright (c) 2025, NexIoT. All Rights Reserved.
 *
 * @Description: 本文件由 gitee.com/NexIoT 开发并拥有版权，未经授权严禁擅自商用、复制或传播。
 * @Author: gitee.com/NexIoT
 * @Email: wo8335224@gmail.com
 * @Wechat: outlookFil
 *
 *
 */

package cn.universal.common.utils;

import jakarta.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class IPUtils {

  private static Logger logger = LoggerFactory.getLogger(IPUtils.class);
  private static final String IP_UTILS_FLAG = ",";
  private static final String UNKNOWN = "unknown";
  private static final String LOCALHOST_IP = "0:0:0:0:0:0:0:1";
  private static final String LOCALHOST_IP1 = "127.0.0.1";

  /**
   * 获取IP地址
   *
   * <p>使用Nginx等反向代理软件， 则不能通过request.getRemoteAddr()获取IP地址
   * 如果使用了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP地址，X-Forwarded-For中第一个非unknown的有效IP字符串，则为真实IP地址
   */
  public static String getIpAddr(HttpServletRequest request) {
    String ip = null;
    try {
      // 以下两个获取在k8s中，将真实的客户端IP，放到了x-Original-Forwarded-For。而将WAF的回源地址放到了 x-Forwarded-For了。
      ip = request.getHeader("X-Original-Forwarded-For");
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("X-Forwarded-For");
      }
      // 获取nginx等代理的ip
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("x-forwarded-for");
      }
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("Proxy-Client-IP");
      }
      if (StringUtils.isEmpty(ip) || ip.length() == 0 || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("WL-Proxy-Client-IP");
      }
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("HTTP_CLIENT_IP");
      }
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getHeader("HTTP_X_FORWARDED_FOR");
      }
      // 兼容k8s集群获取ip
      if (StringUtils.isEmpty(ip) || UNKNOWN.equalsIgnoreCase(ip)) {
        ip = request.getRemoteAddr();
        if (LOCALHOST_IP1.equalsIgnoreCase(ip) || LOCALHOST_IP.equalsIgnoreCase(ip)) {
          // 根据网卡取本机配置的IP
          InetAddress iNet = null;
          try {
            iNet = InetAddress.getLocalHost();
          } catch (UnknownHostException e) {
            logger.error("getClientIp error: {}", e);
          }
          ip = iNet.getHostAddress();
        }
      }
    } catch (Exception e) {
      logger.error("IPUtils ERROR ", e);
    }
    // 使用代理，则获取第一个IP地址
    if (!StringUtils.isEmpty(ip) && ip.indexOf(IP_UTILS_FLAG) > 0) {
      ip = ip.substring(0, ip.indexOf(IP_UTILS_FLAG));
    }

    return ip;
  }
}
